Bidder "B" bids $100. The bid will only appear as $5.50 (one increment over $5). Now if there were two friends, bidders "B" and "C" who bid $100 and $101 then then would both retract for "A" to win the bid at $5.

For example, the recently sold Chesterfield chips sold for $600.01 with a starting bid of $$6. Let's see, I open at $6, Dick Price bids $1000, Steve Snowden bids $1005. You two guys retract at the end. I get the chips for $6, and I turn around and sell one to each of you for $100 each (sorry guys)